Throat plate for sewing machines



June 11, 1929. K. MAIER 1,717,050

THROAT PLATE FOR SEWING MACHINES Original Filed June 13, 1925 Patented June 11, 1929.

KARL MAIEIR, OF STUTTGART, GERMANYfASSIGNOR TO FABRIK, G. M. B. BL, 01 STUTTGART,

UNION SPECIAL MASCHINEN- GERMANY.

THROAT PLATE FOR SEWING MACHINES.

Original application filed June 13, 1925, Serial No. 36,887, and in Germany June 19, 1924. Divided and this application filed October 26, 1926. Serial No. 144,312.

The invention relates to new and useful improvements in throat plates for sewing machines, and more particularly to a throat plate for an over edge sewing mach1ne.

An object of the invention is to provide a throat plate having a removable and adjustable section carrying a stitch finger, which provides a very durable support for the tinger, and which permits of the finger be ng adjusted in a direction parallel with the line of feed.

A further object of the invention is to provide said adjustable section of the throat plate with a second stitch finger, wh ch s not only adjustable therewith, but which is also adjustable independently of the ad just ments of the main stitch finger.

In the drawings:

Figure 1 is a perspective view showing an over edge stitching mechanism and a work support having my improved throat plate attached thereto, and

Figure 2 is an enlarged perspective view of the throat plate.

The invention is directed to a throatplate for an over edge stitchingmechanisin, that is, a stitching mechanism including a needle and complemental stitch forming devices for an interlocking threadloop about the edge of the fabric. The throatplate is provided with a removable section which is adj ustably attached to the main section'of the throat plate whereby it may beyadjusted in a direction parallel with the line of feed. Mounted on this adjustable section of the throat plate is a stitch finge which liesat one side of the needle and is sddisposed that the over edge threads are laid around this stitch finger. The stitch finger terminates a short distance in rear of the needle and is tapered toward its free end so that the thread loops laid over the stitch finger slide ofilfrom the stitch finger when the material is moved along by thej'feeding mechanism. The removable section of the throat plate is provided with a slot extending substantially parallel with the line of feed, and located in this slot is a bar which projects rearwardly from the adjustable section of the throat plate and lies along side of the first named stitch finger. It is, spaced from the stitch finger and also spaced from the wallet the main section of the gated slots 11, 11.

however,-

throat plate. This projecting bar forms a second stitch finger, and the thread loops likewise are laid across the same and slide oii from the end thereof when the material is fed.

Referring more in detail to the drawings, the invention is shown as appliedto a sewing machine having a plurality of needles 1, a work support 2, a throat plate 3 mounted on the work support, a thread carrying looper beneath the work support, and an orer edge thread carrying looper 5. These stitch forming elements produce an over edge stitch. The looper 5-is provided with a plurality of thread eyes arranged one above the other, and each eye carries an independent looper thread, as a result the over edge looper lays a plurality of loops at stitch formation, which loops are nested one within the other.

This stitch forming mechanism and the seam produced thereby form no part of the present invention but are described and claimed in my parent application, Serial Number 36,887, filed June 13, 1925, of which this application is a division, and'in my patent No. 1,640,201, granted August 23, 1927.

The throat plate 3 is slots 6 and 7 in which and the line of feed is of course in a direction lengthwise of these slots. The throat plate 3 is provided with a removable section 8. Said throat plate is recessed so as to form a ledge 9 and the removable section 8 has a portion 10-overlapping the ledge 9. This portion 10 is provided with elon- Screws 12 pass through these slots and are threaded in the ledge 9. By loosening the screws 12 the removable section 8 of the throat plate can be adjustedin'a direction parallel with the line of feed.

The rib 13 of the throat plate which lies between the feed slots 6 and 7 is cut away onits upper face so as to form ledge 14. The removable-section 8 of the throat plate is provided with, a projecting part '15 which overlies theledge 14. This makes a very durable support for the removable section of the throat'plate in the region where the needle is operated. The removable section 8 of the throat plate is rovided with a stitch finger 16. This stitch provided with feed the feed dog works a supporting I finger 16 is tapered at 17 on its lower face, and the said finger projects beyond the rear end of the throat plate so as to provide a slot 18 in which the needle reciprocates. The over edge thread carrying looper lays the thread loops carried thereby over this stitch finger and when the material is moved by the feed dog the thread loops are fed off from the end of the stitch finger. As noted above the over edge looper carries a plurality of threads and thereby a plurality of loops are laid over this stitch finger at each stitch formation. By providing the removable section of the throat plate with a projecting portion 15 a very durable support is formed for this main stitch finger 16. The removable section of the throat plate adjacent the stitch finger 1G is provided with an upwardly and inwardly projecting scroll 19, which serves to infold the edge portion of the material prior to the laying of the thread loops about said edge. i

The removable section of the throat plate is provided .with a recessor groove 20 in its upper face which extends the full length of the removable section of the throat plate. Located in this groove is a bar 21. The bar 21 projects beyond the rear end of the throat plate so as to provide a second stitch finger 22. The bar is held in the groove by'a screw 23 which overlaps 'the bar and clamps it to the throat plate. This stitch finger is separated from the wall of the main section of the throat plate by a slot 24 and when two needles are used in the stitch mechanism'the second needle passes down through this slot 24. By adjusting the section 8 of thethroat plate the position of the main stitchfinger and also the second stitch finger may be shifted relative to the needles and thus the stitch fingers properly positioned to receive the thread loops and allow the same totsl-ide off from the end thereof. The second stitch finger can beadjusted inthe adjustable section of the throat plate and thus the second stitch finger shifted relatively independently of the main stitch finger.

It is obvious that miner changes in the details of construction and the arrangement of parts may be made without departing from the spirit of the invention as set forth in the appended claims.

Having thus fully described my invention, what I claim as new and desire to secure by Letters-Patent, is

1. The combination with an over edge stitch forming mechanism, of a throat plate having feed slots formed therein, said throat plate having a removable section ad justably secured thereto so that said adjustable section can be shiftedtoward and from the stitch mechanism in a direction parallel with the line of feed from one set position to another, and a main stitch finger carried by said adjustable section of the throat plate. v 2. /Ihe combination with an over edge stit 1 forming mechanism, of a throat plate having feed slots fOI'IH GKl therein, said and forming a second stitch finger, and B0 meansfor adjustably securing said barin 'said slot.

3. A throat plate for sewing machines comprising a main section having feed slots and a recess forming a supporting ledge, a removable section overlying said ledge and provided with elongated slots extending ina direction parallel to thelong-itudinal axis of the feed slots, screws passing t lI'Ollgll said slots-for adjustably securing tlr removable section to said supporting ledge, said removable section having astit'ch finger projecting therefrom whereby said stitch finger may be shifted in a direction parallel with the line of feed from one set position to another. set position.

4. A throat plate for sewing machines comprising a main section having feed-slots and a recess formin'gta supporting ledge, a removable section overlying said ledge and provided with elongated slots, screws passing through said slots for adjustably securing the removable section to said support-ing ledge, said removable section having astitch v finger projecting therefrom, and said removable section also having a longitudinal slot in its upper face, and a bar adjustably secured in said slot and projecting along side of the stitch finger to form a second stitch fin er.

5; A t roat plate for sewing machines comprising a main section having feed slots and a cut away portion on-its upper face forming a supporting-ledge, said cut away portion extending along side of one of said feed slots and to a point wellin rear of the stitch finger, a removable section overlying the supporting ledge on the aim section and adjustable lengthwise of thelfeed slots in adirection parallel with'the lineof' feed, 12

said removable section having a projecting portion tapered to form a stitch finger separated from the main section of the throat plate so as to provide a slot for the needle.

. In testimony whereof, I aflix my 'signature.

KARL MAIER. 

